Upon her graduation from the Shimada Chiaki Makeup Academy in Tokyo, Japan, Eiko Watanabe began her career under Tomofumi Itokawa and Youko Kinoshita as their assistant. After completing the assistant internship, she was granted a promotion to become an instructor at Shimada Chiaki Makeup Academy. As an instructor, she specialized in hair and makeup in advertisements, TV, theater, and bridal events. To further her skills, she moved to Los Angeles, California in the United States and attended the Cinema Makeup School where she mastered Special Effects Makeup.